''Euphorbia maculata'', known as spotted spurge, prostrate spurge (not to be confused with ''
Euphorbia prostrata''), milk purslane, or spotted sandmat, is a fast-growing
annual plant
An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. Globally, 6% of all plant species and 15% of herbaceous plants (excluding trees and shrubs) are ...
in the family
Euphorbiaceae
Euphorbiaceae (), the spurge family, is a large family of flowering plants. In English, they are also commonly called euphorbias, which is also the name of Euphorbia, the type genus of the family. Most spurges, such as ''Euphorbia paralias'', ar ...
. It is native to North America, where it is generally considered a common weed, it can be found in disturbed soils such as garden beds, along railroad tracks, and in the cracks of sidewalks. It has become a common
introduced species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...
throughout the world, including Europe, Japan, Korea, Australia, and New Zealand.

It grows in sunny locations and a variety of soils, and functions as a
pioneer species
Pioneer species are resilient species that are the first to colonize barren environments, or to repopulate disrupted biodiverse steady-state ecosystems as part of ecological succession. Various kinds of events can create good conditions for pi ...
in
ecological succession
Ecological succession is the process of how species compositions change in an Community (ecology), ecological community over time.
The two main categories of ecological succession are primary succession and secondary succession. Primary successi ...
. The sap of this plant is a mild skin irritant and can cause a rash in some people. The milky sap of plants in genus ''Euphorbia'' is poisonous and considered carcinogenic.
Description
As originally described in 1753 by
Carl Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
, ''Euphorbia maculata'' is an herbacous plant with small, oblong opposite leaves. The leaves are pilose, or covered in small thin hairs, and generally have a crenate (scalloped) edge. Each leaf is marked with a small brown spot in the center, giving the plant its common name.
''Euphorbia maculata'' is typically prostrate, with specimens rarely reaching as high as . The stems spread out in a mat along the ground with each stem rarely greater than long. The
leaves
A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...
are oval but rather elongate, up to long. The
cyathia, bisexual reproductive structures unique to plants in the genus, are very small, with four white petal-like appendages that are sometimes pink.
''Euphorbia maculata'' flowers in the summer. These flowers develop in clusters near the axillary bud, they are small and leaf-like, with a red calyx. Upon blooming they have lobed, white to pink petals.
["Euphorbia maculata (Spotted Spurge): Minnesota Wildflowers". ''www.minnesotawildflowers.info''. Retrieved 2024-10-24.]
''Euphorbia maculata'' develops a small, 3-lobed fruit. This fruit, like the rest of the plant, is covered in fine, soft hairs. Each lobe is a capsule that contains a single seed. The seeds are small, oblong, and white to light brown. The surface is uneven and covered in little divots.
''Euphorbia maculata'' is similar to ''
Euphorbia prostrata'', but that species has shorter leaves that are more rounded at the tips. It may occasionally be confused with ''
Euphorbia serpens'' but this taxon has very short and rounded leaves and larger (but still inconspicuous) cyathia.
Distribution and habitat
''Euphorbia maculata'' is considered native to all of the continental United States according to the United States Department of Agriculture. Spotted Spurge has been naturalized in much of the world. This includes South America, Australia, Asia, parts of Africa, and throughout Europe.
["Spotted spurge - Euphorbia maculata (Taxonomy, Characteristics, Symbolism, Images, Toxic)". ''PictureThis''. Retrieved 2024-10-24.]
''Euphorbia maculata'' is commonly found along roadsides, in the cracks and crevasses of sidewalks, and throughout North America. It grows in sunny and arid areas without much shade. Spotted spurge grows well in coarse soils, such as sand or gravel, but can also be found growing in compacted soils and areas with poor soil. It grows best in conditions in full sun.
Uses
''Euphorbia maculata'' is understood throughout most of North America as a weed, however it is used in Asia for as a medicinal plant. The species possesses
triterpenoid
Triterpenes are a class of terpenes composed of six isoprene units with the molecular formula C30H48; they may also be thought of as consisting of three terpene units. Animals, plants and fungi all produce triterpenes, including squalene, the pre ...
s that when medicinally applied, have anti-inflammatory and anti-proliferative properties.
Toxicity
''Euphorbia maculata,'' like much of the ''Euphorbiaceae'' is considered toxic. Its effects may include mild skin irritation, which is amplified when exposed to the sun, irritation to the stomach, and vomiting as well as being generally considered a carcinogen. The toxins come from a thin, white, milky sap that is produced when either the leaf or the stem gets broken. Contact with the eyes, skin, or mouth should be avoided.
Weed control
Because ''Euphorbia maculata'' grows quickly in a variety of climates it is seen as a weed throughout much of North America and can be a particularly troublesome weed in crop fields and pastures. The growth of ''E.maculata'' in agricultural fields may impact crops yields such as vegetables, legumes, and cereals. Due to toxicity, the growth of ''Euphorbia maculata'' in pastures can cause sickness, vomiting, and weakness in livestock.
Pre-emergence herbicides are useful where problems have been known to arise and mulching is not possible.
["Spotted Spurge, Chamaesyce (=Euphorbia) maculata". ''Wisconsin Horticulture''. Retrieved 2024-10-24] Mechanical control is hand pulling of the entire plant, roots included, to prevent regrowth. Another non-chemical control method is to apply a thick layer of mulch to the affected area. Spotted Spurge grows best in open, sunny areas, so mulching with a layer wood chips or straw prevent may smother the plant.
References
External links
*Missouriplants
''Euphorbia maculata''
{{Taxonbar, from=Q177322
maculata
Flora of Northern America
Plants described in 1753
Taxa named by Carl Linnaeus